Electronic properties and surface reactivity of SrO-terminated SrTiO3 and SrO-terminated iron-doped SrTiO3
Author(s)
Type
Journal Article
Abstract
Surface reactivity and near-surface electronic properties of SrO-terminated SrTiO3 and iron doped SrTiO3 were studied with first principle methods. We have investigated the density of states (DOS) of bulk SrTiO3 and compared it to DOS of iron-doped SrTiO3 with different oxidation states of iron corresponding to varying oxygen vacancy content within the bulk material. The obtained bulk DOS was compared to near-surface DOS, i.e. surface states, for both SrO-terminated surface of SrTiO3 and iron-doped SrTiO3. Electron density plots and electron density distribution through the entire slab models were investigated in order to understand the origin of surface electrons that can participate in oxygen reduction reaction. Furthermore, we have compared oxygen reduction reactions at elevated temperatures for SrO surfaces with and without oxygen vacancies. Our calculations demonstrate that the conduction band, which is formed mainly by the d-states of Ti, and Fe-induced states within the band gap of SrTiO3, are accessible only on TiO2 terminated SrTiO3 surface while the SrO-terminated surface introduces a tunneling barrier for the electrons populating the conductance band. First principle molecular dynamics demonstrated that at elevated temperatures the surface oxygen vacancies are essential for the oxygen reduction reaction.
Date Issued
2018-03-02
Date Acceptance
2018-02-09
Citation
Science and Technology of Advanced Materials, 2018, 19 (1), pp.221-230
ISSN
1468-6996
Publisher
Institute of Physics, National Institute for Materials Science
Start Page
221
End Page
230
Journal / Book Title
Science and Technology of Advanced Materials
Volume
19
Issue
1
Copyright Statement
© 2018 The author(s). Published by national i
nstitute for Materials Science in partnership with Taylor & Francis. This is an open access article distributed under the terms of the creative commons a
ttribution license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
nstitute for Materials Science in partnership with Taylor & Francis. This is an open access article distributed under the terms of the creative commons a
ttribution license (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/29535797
PII: 1440136
Subjects
401 1st principle calculations
50 Energy Materials; 207 Fuel cells / Batteries / Super capacitors
DFT
oxygen reduction
perovskites
surface chemistry
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2018-02-13